[Determination of the proliferative activity of breast cancer cells using 5-bromo-2'-deoxyuridine in vivo].

Proliferative activity was studied by immunohistological assay of label index (LI) involving the injection of 5-bromo-2'-deoxyuridine in vivo into 10 benign lesions and 40 breast tumors. LI level was found to be significantly higher in breast cancer patients (10.94%) than in cases of benign lesions (1.97%) (p = 0.000002). A similar relation was recorded between relapsed breast cancer (16.65%) and primary tumor (10.28%) (p = 0.03). The study also established a distinct correlation between LI of invasive ductal carcinoma and histological malignancy as determined according to Bloom and Richardson, p = 0.045 between stages I (6.03%) and II (9.60%) and p = 0.01 between stages II and III (15.37%), the ability to form tubular structures (p = 0.003), the numbers of mitoses and hyperchromatic nuclei (p = 0.006) between stages I (5.95%) and II (9.53%) and p = 0.003 between stages II and III (15.00%) and presence or absence of nuclear polymorphism (p = 0.03%). No correlation was observed between LI in breast tumor, on the one hand, and tumor size, degree of invasion, clinical stage, age, menstrual status and estrogen and progesterone receptor levels, on the other. LI in metastasis (7.07%) (15 cases) appeared to be significantly higher than in primary tumor (10.13%) (p = 0.001) and it revealed a distinct correlation with that in primary tumor (p = 0.39).